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78 ford 400. BB or SB?

6K views 47 replies 19 participants last post by  caveman 
#1 ·
a 400 from a 78 f150 would be a big block or small black?:nana:

or the question is, can i remove the engine (400) and put a 460 or 429 on the same trans...
 
#4 ·
The 400/351M is a big block, it is a 351bigblock with 400 heads on it. It was used in Full size pickups and broncos in the late 70's to early 80's. It was discountinued and replaced the the 5.8L 351 small block because the 351M was found to be unreliable and constantly having problems.
 
#5 · (Edited)
i disagree, those motors ran forever.

you'll have to change the exhuast also which isnt easy cause car manifolds run into the passenger side frame. The torque converter snout is a different size going from a 400 to a 460.
It's really a small block with a big block bellhousing bolt pattern. They take the same size pistons as a 351 cleveland except the wrist pin is a different size.
351m and 400 heads are identical, the only difference between the 2 is the crank and pistons.
 
#6 ·
i disagree, those motors ran forever.

you'll have to change the exhuast also which isnt easy cause car manifolds run into the passenger side frame. The torque converter snout is a different size going from a 400 to a 460.
It's really a small block with a big block bellhousing bolt pattern. They take the same size pistons as a 351 cleveland except the wrist pin is a different size.
I disaggree, I have done this swap, all I needed was the engine mounts from jeff's bronco graveyard, then it bolted right in. Didn't have to change anything else at all.

If the 351M was such a good motor then why is everyone junking them and going to a 351C, 351W, or 460bb.
 
#7 ·
Like Ken said It is a small block with a big block 429/460 bolt pattern. The cam and I believe the heads and other parts were same as 351 Cleveland. Both 351M and 400 used same heads only difference was longer stroke. Car Craft did a budget build on a 400 and got 390HP and 450 ft lbs torque on a 2 barrel carb
 
#11 ·
Mine ran great for over 15 years and that was after years of abuse as a car hauler/wheeler in west branch. I left the hood off of it for a year in my back yard and water got in it and rusted it up. That is the only reason that I going to go with a 460. 400 with hooker headers/edelbrock intake and a Holley 650 worked great had tons of power.

i have many spare parts including the couple hundred mile hooker super comps if anyone is still running a 351M..

And yes from what I have read they are a small block (351C) stroked with a big block bell housing.

Here is a good read on the history of them

http://home.earthlink.net/~bubbaf250/history/history03.html
http://www.broncotech.com/351M.html
 
#24 ·
There were two engine types in the Ford engine family known as the 335 series, the 351 Cleveland (351C) and the “M-block.” There were several minor variants of the 351C engine (including the basic 2V and several high-performance 4V versions), but there were only two M-block variants — the 351M and the 400. From 1971 to 1982, Ford manufactured millions of M-block engines for use in mid-sized cars, full-sized cars, luxury cars, and light-duty trucks.

The 400 featured a unique engine block design with the big-block (429/460) bell housing bolt pattern, and the same bore diameter (4.00") and bore spacing (4.38") as the 351C and the later Windsor-class small blocks (i.e., 289, 302, and 351W).

Compared to the 351C block, the 400’s deck height is over 1" taller (10.297" vs. 9.206"), the 400 has larger crankshaft main bearing journals (3.00" vs. 2.75"), and the 400 uses longer connecting rods (6.58" vs. 5.78"). The 400 achieves its additional 49 cubic inches of advertised displacement with a 4.00" stroke of the crankshaft (compared to the 3.50" stroke of the 351C). The 400 has the longest stroke of any Ford pushrod V8 engine.

Both engine types in the 335 series (351C and M-block) share many design characteristics, but the only major component that is interchangeable between 351C and M-block engines is the cylinder head. Several internal components and accessories interchange, including camshafts, timing sets, water pumps, fuel pumps, oil pans, distributors, and thermostat housings. All 335-series engines are externally balanced with a 28 oz-in imbalance on the crankshaft (the same as 302 and 351W engines up to 1982).
 
#25 ·
its funny that I must be the only one here that likes the 351/400 for what it is. I helped my neighbor take out a 429 and put back the 351M in his `79 F250. I am kinda the nut case in favor of bigblocks , but when putting them in a 4x4 they kinda get nose heavy. the 460 is 690lbs VS. the 351M 540lbs thats a huge savings when looking and staying a float in deep mud. the other big reason not to do a 351M swap is fuel milage. you can bet your cowboy hat & your house cat that best you will get is 8-10 with a 460 in a 4x4 truck. I could barely get 5-6 mpg in my `85 dually and it was 2wd.
 
#27 ·
Don't tell me that I should have kept my 351M I am still crying that I found out it was already bored .060" over when I tore it down.

So if I was going to bother with a BB 460 or 429? Sorry for the hijack

And yeah Bill if the "460" is in a F150 it did not come from the factory that way . Correct me if I am wrong but only F2 and 350's and some cars came with the BB right?
 
#31 ·
couple of things... 429/460 didn't come in F150 or F250 4x4s from the factory. it made the front to heavy. the majority of BB stuff came as trailer tow packages in the Camper Specials F250/F350 stuff. even the F600/800 stuff have the luxury of the 377/429 package because they rev high for the high toqure at low speed.

If you had a Cougar they would accept the 460 untill they dropped the body size in `80. theres some very rare 460 bellhousing on C4's if you find one the swap is notheing more then engine mounts and brackets. the C6 is about 8" longer and with all the high performance stuff you can build the C4 to ba as strong as a C6. I did the BB swap in my buddys cougar and we had to cut down the driveshaft to get the C6 in.

Muddypaws. If I remember right the 351C ended its production run in `73. the 351/400Ms started in after that. so if you have one after `74 its most likely a "M" engine.
 
#33 ·
You could also get a 400 with a small block bellhousing, but only in 74, and it was in front of a FMX.

351M's really aren't worth much more than scrap value, simply becuase they are EVERYWHERE. Now 400's, quite a bit harder to come by, and really have some potental. It's hard to go wrong with a 4" stroke.

The big issue with them though, is the piston is nearly .070" down in the hole, so if you just put flat tops in them, they have detonation issues. The key is to either zero deck the block, or to get the pistons with a taller compression height to fix the problem. the two thing's a M motor lacks from the factory is compression, and cam(mainly cam timing)

My buddy put one together for his rig last spring that runs really, really strong. 79' 400, stock compression, .519/,522 lift cam, performer 400 intake, ~780ish holley, and headers. Runs very strong, and builds gobs of torque.

Seen one at the mud drags last weekend that made really good power as well, 10.5:1 compression, aussie heads, and some other goodies.. very fast bronco..
 
#36 ·
easy, look at how many 351M's there are out there, and then look at how many 400's there are around...

Its the crank that is hard to find..
 
#35 ·
460s up until 1979 were internaly balanced. I had to use a 390 or centerforce flywheel with my 1971 460. I chose the centerforce (40.5 lbs).

When I junked my knocking 400 in my bronco, I gained about 1.5mpg with the 460. Although 10 is nothing to brag about.

You have to watch out on some 400s from the junkyard. The 1972 400 (or what ever the first year production was) had a small block bell housing.

To answer the question BB or SB, it's neither. It's a 335 series Ford engine. The 370/429/460 was the 385 series. The 330/352/360/390/406/410/428 was the FE series (Ford Edsel). Confused yet?
 
#38 ·
460s up until 1979 were internaly balanced. I had to use a 390 or centerforce flywheel with my 1971 460. I chose the centerforce (40.5 lbs).

When I junked my knocking 400 in my bronco, I gained about 1.5mpg with the 460. Although 10 is nothing to brag about.

You have to watch out on some 400s from the junkyard. The 1972 400 (or what ever the first year production was) had a small block bell housing.

To answer the question BB or SB, it's neither. It's a 335 series Ford engine. The 370/429/460 was the 385 series. The 330/352/360/390/406/410/428 was the FE series (Ford Edsel). Confused yet?

I am wondering where you found your facts?
some of what you posted is flat ass wrong.

460's are EXterally balenced always have been since `68. the 429's came as Interally balenced. the Boss 429 could be ordered either way or not at all.

last I knew 390(fe) flywheels didn't ever mount to a 429/460 engine, secondly they are internally balenced. which wouldn't work on a 460 anyways. also the dia. of the flywheel is wrong. if I remember right the 429/460 used a 142 tooth wheel. the 390/428 used a 136 tooth. now I can beleive you used a 428 flyweel on a 390 or vise versa, but the 385 series engines parts didn't interchange.

by the way out of the engines you listed under FE the 410 is the only one thats is externally balenced and it never came as a standard trans. I had to make a flywheel for one once.
 
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